How to beat tutsan
Location: throughout the North Island and mainly in wetter areas of the South Island, plus Stewart, Chatham and Campbell Islands
Distinctive features: this small (up to 1.5m) perennial, semi-evergreen shrub from Europe is related to the ornamental hypericums. It has the same distinctive yellow flowers, although on a smaller scale. Flowers are followed by round red berries that ripen to black. The fragrant oval leaves are usually bluish underneath and can turn red in autumn.
Where will you see it: it takes hold in areas of disturbed forest and shrubland, tussockland, bare land and rocklands, usually in areas with high rainfall, forming dense stands.
Why is it weedy: it produces long-lived, well-dispersed seeds which are spread by birds and possibly possums into bush areas. It tolerates semi-shade and a wide range of temperatures, and invades regenerating bush sites.
How does it spread: once berries turn black and ripen, they disintegrate, spreading large amounts of dust-like seed over a wide area.
Look out for small, bright yellow, five-petalled flowers,followed by fleshy,round, red berries,which ripen to black